"""TapeOutScan API: Python 3 standard library only.
Set TOS_API_KEY and TOS_API_SECRET in your server environment before running.
Never embed the secret in website JavaScript or a public repository.
"""
import hashlib
import hmac
import json
import os
import secrets
import time
import urllib.error
import urllib.request

# Sign the EXACT path + query sent to the server, including parameter order.
target = '/v1/circuits?chainId=56&collection=30&limit=20'
timestamp = str(int(time.time()))
nonce = secrets.token_hex(16)
message = '\n'.join(['GET', target, timestamp, nonce, hashlib.sha256(b'').hexdigest()])
signature = hmac.new(os.environ['TOS_API_SECRET'].encode(), message.encode(), hashlib.sha256).hexdigest()
request = urllib.request.Request('https://tapeoutexplorer.com' + target, headers={
    'X-TOS-Key': os.environ['TOS_API_KEY'],
    'X-TOS-Timestamp': timestamp,
    'X-TOS-Nonce': nonce,
    'X-TOS-Signature': signature,
    'Accept': 'application/json',
})
try:
    with urllib.request.urlopen(request, timeout=10) as response:
        payload = json.load(response)
        print(json.dumps(payload, ensure_ascii=False, indent=2))
except urllib.error.HTTPError as error:
    print('HTTP', error.code, 'Retry-After:', error.headers.get('Retry-After'))
    print(error.read().decode())